Category Archives: Weather
[Source: EurekaAlert] — Protect yourself from the summer sun is good advice to children who want to play outside on a hot summer day and it is good advice to cities as a way to mitigate the phenomenon known as urban heat island. For children, a hat, long sleeves and sun block provide protection. For cities, it might be canopies, additives to construction materials and smarter use of landscaping that helps protect it from the sun, said Harvey Bryan, an ASU professor of architecture. Bryan presented several possible strategies a city could use to help it fight urban heat island (UHI) in a presentation he made at the annual meeting of the American Association for the Advancement of Science, held in San Diego, Feb. 18 – 22. Bryan’s presentation, “Digital Simulations and Zoning Codes: To Mitigate Urban Heat Island,” was presented on Feb. 21 in a session on Urban Design and Energy Demand: Transforming Cities for an Eco-Energy Future.
Urban heat island is a phenomenon experienced by large cities, especially those located in desert areas, where the constant heat of the day is absorbed by the buildings, pavement and concrete. The result is a rise in nighttime low temperature for a city’s core from the stored heat of the day. The higher nighttime temperatures mean more cooling is required for residents’ comfort, resulting in increased power demand and potentially more greenhouse gases emitted. Phoenix, where summer nighttime temperatures often do not go below 90 F, is a classic example of the UHI, Bryan said.
Citing work he participated in about a year ago – with Daniel Hoffman, an ASU professor of architecture and Akram Rosheidat, an ASU doctoral student – which focused on ways of improving pedestrian comfort in downtown Phoenix, Bryan outlined several methods a city can employ that will help alleviate the UHI. Shade, not surprisingly, is one of the prime tools. “Canopies to shade streets and sidewalks keep the concrete and asphalt cooler,” Bryan explained. “Interestingly, sidewalks in downtown Phoenix during the early 1900s were canopied.”
Bryan said another key aspect is being smart on material choices for the canopies. “In addition to shading devices, color and thermal properties are also important considerations,” Bryan said. “Lighter colors are best for any surface in the Valley. You also have to consider the heat capacity of the materials – denser material will absorb heat during the day and are slow at re-emitting at night.”
In areas that cannot be canopied, Bryan said material additives use could play an important role. Phoenix, for example, has a large number of parking lots and streets that constantly absorb daytime heat. “Introducing additives, like crumb rubber to asphalt and concrete, are ways of reducing heat capacity at the surface and making for a better nighttime profile,” he said. “The important part is to look at materials performance more than just during the daytime. We need a 24-hour profile to see how materials absorb heat during the day and how they emit it during the evening. We then look for materials that are reflective during the day and highly emitting during the evening.”
All of this points to modeling as an important tool in mitigating UHI. “It comes down to how we model the downtown and how we look at various scenarios with different materials using models that accurately simulate the radiative phenomena,” Bryan explained. “Most cities have never used such powerful tools to find solutions to UHI.”
Downtown Phoenix the day after a large rainstorm. Video shot by Carl Stevens with a Canon 20D.
[Source: Jim Cross, KTAR Radio] — Arizona has its share of active earthquake faults, but Phil Pearthree with the Arizona Geological Survey says it’s unlikely those faults are capable of producing a 7.0 quake such as the one that left Haiti in ruins. “Yuma is pretty close to the San Andreas Fault system and, therefore, the seismic hazard is greatest in Yuma,” said Pearthree. “There are quite a number of faults — not as active — but there are quite a number of faults in northern Arizona.”
The largest earthquake to have a significant effect on Arizona happened in 1887 — a 7.0-plus quake in Mexico, not far from Douglas in southeastern Arizona. Pearthree said the probability of a 7.0 quake in Phoenix “is not very high.” Should it happen, he said it would damage stucco homes in the Valley, but big buildings in downtown Phoenix would be able to withstand it. “It depends on the age of the structure and when it was built,” he said. “Obviously, the modern structures are typically built better and large structures are build to withstand even the winds.”
A 7.0 quake would be more likely to happen in the Los Angeles area than the Valley and the damage there would be far less damage than in Haiti, Pearthree said. “They had an earthquake in ’94 that was right in the Los Angeles area, more or less, and it was almost as big. There was damage and people were killed, but there wasn’t widespread devastation, so I think building standards do make a difference.”
Northern Arizona had several 6.0 quakes in the early 1900s, Pearthree said. [Note: To read the full article, visit Big earthquake in metro Phoenix unlikely.]
[Source: Fox 10 News] — Arizona Gov. Jan Brewer is caught on camera making a remark you wouldn’t expect. The state’s budget battle apparently prompted her to refer to the State Capitol as a “hell hole.” No doubt the state’s budget battle taken its toll on Gov. Brewer — enough to get her to say something surprising during a stop in Tucson.
She told a group of Republicans at the Tucson Country Club: “It’s a great relief to say the least to get out of that hellhole in Phoenix.”
Her office says she wasn’t referring to the city of Phoenix — instead, the state Capitol. Not because of the building, but because of the budget battle.
It’s been a trying few months for Brewer as she’s tried to solve the state’s huge budget deficit. Brewer has been pushing for a 1-percent sales tax increase, but lawmakers in her own party have fought back against it. The governor expects to call lawmakers back to work soon to try and resolve the remaining budget issues.
[Source: Kate Bolnick, ASU Web Devil] — Arizona’s pollution levels showed improvement in Maricopa County in this year’s ozone season, the time of the year when pollution levels are the highest, an official said. “This year, so far, we have four exceedance days for Maricopa County,” said Maricopa County Air Quality Department spokeswoman Holly Ward. “Last year we had 18 exceedance days reported.”
Exceedance days are the number of days when at least one of the county’s monitors exceed the ozone standards, Ward said. “There [are] some core components that this department strives for… the first and foremost is to reduce the number of times [Maricopa County] exceed[s] the public health standard,” she said.
The public health standard comes from the Environmental Protection Agency’s Clean Air Act of 1970, which was amended in 1990. The standard was raised in March of 2008 to .075 parts-per-million. The act clarifies what level of pollution is acceptable and specifies only one exceedance day every three years is allowed. Arizona is in great violation of the standards, according to the act, but is improving, Ward said. [Note: Read the full article at Maricopa County pollution levels improving.]
[Source: Shaun McKinnon, Arizona Republic] — Heat discriminates. Phoenix’s sweltering summer inflicts the most misery and illness in poor neighborhoods, a new study shows, and among people least able to protect themselves from the elements. Conditions in those neighborhoods, with their sparse landscaping, high-density housing and converging freeways, create pockets of extreme heat that persist day and night. Inside, homeowners sometimes can’t afford to turn up — or even turn on — the air-conditioner.
Wealthier homeowners, meanwhile, often in neighborhoods just blocks away, maintain lush yards and trees that help cool the air more quickly at night, shortening the hours of the hottest heat waves. They can buy further relief with a nudge of the thermostat.
The disparities present threats more serious than just discomfort on a hot day, according to the study, produced by Arizona State University researchers. Prolonged exposure to heat can cause illness or even death. The densely developed nature of the hottest areas also means more of the people most vulnerable — the elderly, children, the homebound — live in the neighborhoods where the risk is greatest.
That link between money and the ability to cope with extreme weather emerged clearly in the research. Among the startling revelations: For every $10,000 an area’s income rises, the average outside temperature drops one-half degree Fahrenheit. “It’s an environmental-justice issue,” said Darren Ruddell, a geographer who led the study. “The people who are most vulnerable are also living in the worst conditions. It’s a double whammy.”
The researchers say they hope their findings will spur discussions about better managing land, water and energy use, factors that will grow more critical if temperatures rise in coming years, as climate-change models predict. “If we can identify the areas most at risk, we can try to help them,” Ruddell said. “We could redesign neighborhoods, build cities differently, improve warning systems and ultimately reduce our vulnerability to heat.” [Note: To read the full article, visit ASU study: Wealth buys rescue from metro Phoenix’s urban heat island. Corresponding PDF graphic here.]
[Source: Colton Shone, KTAR Radio] — The warm temperatures are making it extra tough on the Valley’s homeless population. At the Human Services campus in downtown Phoenix, many people are seeking shelter, but some have to be turned away. “There’s not endless resources for this sort of thing, especially now that we have a 60 percent increase in the homeless population,” director Arlene Pfeiff-Maraj said.
Pfeiff-Maraj says the shelter expects about 1,000 people Thursday night but can only hold 450. Another 300 will stay in a nearby warehouse, and the rest will sleep in the parking lot. [Note: Read full article at Phoenix homeless seek refuge from heat]
[Source: Forbes.com] — While migration to the sunny climates of the Phoenix metro area has certainly slowed — in 2006, the region saw an increase of 4.1%; in 2007, that number dropped to 3.3% — it’s still significantly higher than most metros in the country. The unemployment rate for January 2009 was 6.7%. [Note: To read the full article, click here.]
The new blog, “Phoenix Cycle Chic,” promotes cycling as an alternative form of transportation in Phoenix. Click here to learn more.
[Source: Lisa Biank Fasig, Phoenix Business Journal] — Phoenix has gone to the pits again, ranking as the sweatiest city in six of the past eight years. The dubious honor is handed out by the Procter & Gamble Co. brand Old Spice, which since 2002 has measured the country’s sweatiest cities.
Phoenix has led the Annual Top-100 Sweatiest Cities list for the fourth consecutive year. Over the time of the competition, the city has yielded an average summertime temperature of 94 degrees. The result? The average Phoenix resident producing 27.7 ounces of sweat per hour — the equivalent of more than five gallons of milk per day. Following Phoenix on the list are San Antonio, Texas; Las Vegas; Dallas and Houston. [Note: To read the full article, click here.]